Ask HN: How common are applications of scale these days?

I've been reading lots of material on the side of my day job lately. Clean Code, Martin Fowler's Refactoring, and other similar books. Titles that look at OOP and help you make sense of complicated programming patterns.

However, I've been in the industry for ten years now, and worked for four separate companies, and I'm yet to do anything overly complicated with OOP that requires anything like a complicated class structure, architecture, or design. So far everything seems to be fairly simple and I rarely find myself thinking that hard about design.

I still try to follow best practices and write modular code etc, but I'm wondering if my experience in the software industry is an exception or the norm? Has the industry changed recently, and most developers are no longer building complex, scaled applications? And are some of these classic books on best practices a little out of date now?